There are different gadgets for the same application; however the difference between our device and others is that other units are based on a little ball that acts like a valve, allowing the passing through of fluids without coming back. This devices consists on a storage or chamber that contains the liquids and within this chamber there is a sphere that when the chamber is filled with fluid it floats above the surface of the fluid and allows it to pass through an orifice. As the level of urine decreases, the sphere descends until it sets in the base of the device and by its own weight seals the orifice, this is optimal and stable.
This is because there is no relation in this devises between the diameter and weight of the little ball with the conicity of the base and the diameter of the exit pierce. In the case of the ball if it is too light, it will allow an almost instant drainage with too little residual urine, but since It is so light the mere pressure of the drain gases that normally is of 0.1 bar, may provoke that the ball floats easily allowing the passing of bad odors; on the opposite case if the ball has a superior weight it will allow a good seal, but It will provoke a urine saturation that in some cases may even be visible in the urinal, besides it will generate a greater amount of residual urine, as for the base or ball base in this devices there still isn't a known relation between the conicity and the exit pierce, for that reason this units won't have an optimal functioning, either because there is no relation between the diameter and the weight with respect to the little ball or because there is no relation between the little ball with the conicity and the diameter of the liquid exit pierce.
As some example of the devices of the state of the art we can mention the disclosed units in the Mexican patents WO2012141565 and the WO2012039593, both property of Helvex S.A. de C.V. Also relevant is PCT patent application WO2012064167 that is property of Helvex S.A. de C.V.
Structurally the sealing device for the dry urinal shown in this register is characterized to include a storage with a base in the bottom of the chamber with a decline conformation toward the center and a sphere that whenever the urinal is not being used seals with its weight the exit orifice of the base, and when the urinal its being used and the urine level reaches a certain level this sphere floats and stops sealing allowing the passing through of the urine from the chamber and into the drain, through the base orifice.
Nevertheless, even when the weight of the little ball is taken into consideration, there is no consideration regarding the relation of the diameter with the weight of the sphere neither is related the sphere with the diameter of the exit and the inclined plain of the base, for that reason since it is not taken into consideration such links, it makes that the device lacks of a stable sealing and with a greater amount of residual urine, that generates bad odors.
However, even though the design of this valves has improved in many ways, this improvement can't go further, because since the gas pressure is variable in the drainage, if the little ball was designed to be too heavy as to resist any pressure, it may put at risk the opening by floatation of the little ball. Namely, the urine passes through the exit because the little ball floats, and accordingly with Archimedes principle, it will float whilst the dislodged liquid (the urine that makes the little ball float) has the weight of the little ball.
Therefore, if the little ball is designed to be too heavy as to assure that the seal will prevent the passing of the drain gases, two thing occur, on one side that the residual urine in the chamber is too much and will any way provoke bad odors where the chamber is located in the urinal, or that in order for the ball to float and have the proper weight is designed to be too big, and it will be necessary to design a larger valve with a larger base, increasing the valve's selling price and calling for the urinal to be redesigned with all the implications in the design change.
Until now there have been 3 principles to achieve the seal that allows dry urinals to be accepted. The first was a hydraulic oil seal that allows the passage of urine to the drain and having a density greater than the oil and being Immiscible, then the urine passes and the oil serves as a barrier to drainage gases. This way of performing the seal has the inconvenient that the oil is dragged to the drain progressively and from time to time it must be changed.
The other is the seal provoked by the adhesive qualities of the internal walls of a very flexible hose, that from the effect of the liquid's weight that tries to circulate within it, expands its walls, allowing this way for the liquid to pass through, and once the weight stops acting the walls adheres among them sealing the passing through of the drain gases. In this case the same pressure of the gases tends to unite the walls provoking a better seal. This structure takes advantage of the pressure that is generated from the gases that are meant to be stopped, in order to prevent its exit. The problem with this seal is that the salts contained in urine will progressively be embedded in the walls and the seal will be increasingly inefficient requiring a frequent maintenance.
Finally we have the little ball seal that has already been analyzed and has a very good performance but has the inconvenience of not responding to normal changes of the pressure of the drain gases.
On the other hand, many of the valves for urinals allows the passage of bad odors coming from the drainage, many do not resist cleaning with commonly used chemicals, such as chlorine, sarricides, detergents, etc.
Also the useful life of many is very short, having to be doing corrective maintenance frequently.